COMPACT ULTRA-WIDE-BAND ANTENNA WITH BAND REJECTION CHARACTERISTICS

With the development of wireless communications, ultra-wide-band (UWB) technology has been regarded as one of the most promising technologies in the wireless world because of their attractive features, including high-speed data rate, extremely low spectral power density, high-precision ranging, low complexity and low cost, robustness to multi-path fading and very low interference. These applications make the Federal Communications Commission to dedicate 7.5 GHz of the spectrum from 3.1 to 10.6 GHz for UWB radio applications. One of the key issues in the UWB communications is the design of a compact antenna while providing wideband characteristics over the whole operating band. Owing to the rapid development of such an UWB system, a great deal of attention is being given for the designing of the UWB antennas. This is quite challenging in satisfying the requirement of the UWB, such as ultra-wide impedance bandwidth, omnidirectional radiation pattern, constant gain, high radiation efficiency, constant group delay, low profile and easy manufacturing.